1. Field of the Invention
The present invention relates to a journal bearing for an internal combustion engine and, more particularly, to a journal bearing having an eccentric lubricant supply groove which meters the flow of lubricant through the bearing.
2. Description of the Relevant Art
Typical internal combustion engines utilize journal bearings to mount the crankshaft in the block and to secure the connecting rods to the crank pin journals. The journal bearings typically comprise a pair of semicircular inserts or bearing shells which are retained in a cylindrical bore in the connecting rod or block, wherein half of the bore is formed by a removable cap provided to permit assembly of the journal and the bearing shells within the bore. Recesses formed at the split line between the two semicircular inserts are provided to prevent excessive wear or failure of the insert caused by "close-in" or slight misalignment of the shells during assembly. Without such split line recess, the reduction in bearing clearance at the split line may result in excessive wear or failure of the insert.
Also typical of journal bearings used in internal combustion engines, is the provision of a lubricant supply groove formed in the upper bearing shell which is connected, through a lubricant supply passage, to the oil gallery of the engine. The lubricant supply groove assures an adequate supply of oil to establish a lubricating film between the journal and the inner face of the bearing shell. The lubricant supply groove will typically extend along the entire inner circumference of the bearing shell resulting in a substantial flow path of lubricant to the split line and a correspondingly substantial oil pressure penalty which affects the engine's entire lubricating system.